This is molarity: moles of solute/liters of solution. (Not molality)
1. Plug in what we know:
500 mL = 0.5 L
0.80 = moles/0.5
0.80*0.5 = moles
moles = 0.4
2. NaOH is given as 40 g/mole, so calculate the grams:
0.4 * 40 = 16 grams
answer: 16 grams
Answer:
15.95
Explanation:
This question is a modification of the calculation of the empirical formula of a compound given its percent composition and atomic weights of the elements in the compound.
Here we are given the formula and the percent composition, so we know that there are 4 atoms of E per 2 atoms of N so lets solve using the information given.
In 100 grams of the binary compound we have
30.46 g N
69.54 g E
The number of moles is the mass divided by atomic weight:
mol N = 30.46 g / A.W N = 30.46 g / 14.00 g/mol = 2.18 mol N
mol E = 65.54 g / A.W E
Thus,
4 mol E/ 2 mol N = ( 69.54 g/ A.W E ) / 2.18
2 A.E = 65.54 g / 2.18 ⇒ A.W E = 69.54 g / ( 2 x 2.18 ) = 15.94 g
So the A.W is 15.94 g/mol which is close the atomic weight of O.
(2) 2 - 7 - 18 - 7 does, because the electron from the L shell jumped to the N shell, which requires energy.
The rest of them are either different types of atoms (different elements) or are not the excited state (ground state)
Answer:
Fe(CN)₂, FeCO₃, Pb(CN)₄, Pb(CO₃)₂
Explanation:
Cations (positively charged ions) can only form ionic bonds with anions (negatively charged ions). However, you can't just simply put one cation and one anion together to form a compound. Each compound needs to been neutral, or have an overall charge of 0. When cations and anions do not have charges that perfectly cancel, you need to modify the amount of each ion in the compound.
1.) Fe(CN)₂
-----> Fe²⁺ and CN⁻
-----> +2 + (-1) + (-1) = 0
2.) FeCO₃
-----> Fe²⁺ and CO₃²⁻
-----> +2 + (-2) = 0
3.) Pb(CN)₄
-----> Pb⁴⁺ and CN⁻
-----> +4 + (-1) + (-1) + (-1) + (-1) = 0
4.) Pb(CO₃)₂
-----> Pb⁴⁺ and CO₃²⁻
-----> +4 +(-2) + (-2) = 0
Answer:
True statment
2) Styrofoam would make a good calorimeter
3) Insulating material would make a good calorimeter
Explanation:
The calorimeter is one which is insulated that is which will not absorb or let the heat to escape from it. the calorimeter is used to measure the heat change during a process so if it will allow to exchange heat with surrounding it will deviate the readings or observence.
Copper is a good conductor of heat so we cannot use it make a calorimeter.
Hence
1) Copper would make a good calorimeter : False
2) Styrofoam would make a good calorimeter: True
Styrofoam is a bad conductor or insulator so it can be and it is used for calorimeter.
3) Insulating material would make a good calorimeter
: True
4) A good calorimeter should easily absorb heat : false
